Post-Triassic Spermatophyta Timetree Adding the Quaternary Radiated Asarum Wild Gingers [post]

Soichi Osozawa, Cunio Nackejima, John Wakabayashi
2020 unpublished
BackgroundAngiospermae radiation was known as the mid-Cretaceous event, but adaptive radiation of Asarum is also expected in the Quaternary. In order to know such the Angiospermae evolutionary history through the time, we constructed a whole Spermatophyta timetree employing BEAST v1. X associated with robust fossil calibration function.ResultsWe successfully and precisely dated the Spermatophyta phylogeny, and the Angiospermae topology was concordant to the APG system. Using another function of
more » ... BEAST, we discovered the exponential increase in base substitution rate in recent geologic time, and another rise of rate at the mid-Cretaceous time. These increasing events correspond to the Quaternary and mid-Cretaceous Angiospermae radiations.ConclusionsA probable cause of the recently increasing rate and the consequent radiation was ultimately generation of C4 grasses, reduction of atomospheric CO2, and the start of the Quaternary glacial period. Mid-Cretaceous event was explained by co-radiation with insect beetles as the food plant.
doi:10.21203/rs.3.rs-99466/v1 fatcat:3sia2v2tqjft5ofl6xaplrjpti